Wireless-telegraph system.



No. 827,524. PATENTED JULY 31, 1906. L. DB FOREST.

WIRELESS TELEGRAPH SYSTEM.

APPLICATION FILED JAN. 2. 1906 2 SHEETS-SHEET 1.

No- 827,524. PATENTED JULY 31, 1906. L. DB FOREST.

WIRELESS TELEGRAPH SYSTEM.

APPLICATION FILED JAN. 2. 1906.

2 SHEETS-SHEET 2.

J v (id UNITED STATES,

PATENT OFFICE.

Specification of Letters Patent,

Patented July 31, 1906.

To all whom it may concern.-

Be it known that I, LEE DE Fonhs'r, a citizen of the United States, anda resident of New York, in the county of New York and State of New York,have invented a new and useful Improvement in Wireless-TelegraphSystems, of which the following is a specification. 7

M invention relates to wireless telegraphy and as for its object asystem which is rovided with a transmittin and a receiving apparatus,both associate with one antenna, and with means whereby a receivingoperator is enabled to cut in uponand interrupt a transmitting operatorat another station.

In the drawings, which accompany and form a part of this specificationand which illustrate dia ammatically one system of circuits where y myinvention may be carried into efiect,Figure 1 represents awireless-telegraph transmitting and receiving system, and Fig 2represents a modification of a detail of construction.

Heretofore I have described a wireless-telegraph system which isprovided with separate transmitting and receiving antennae at the samestation and associated apparatus operated by the transmitting-key wereby a receiving operator may interrupt the transmission for a distantstation; but it is obvious that in certain locations,-for example, onshipboard,-'only one antenna is permissible, and with .the. system whichforms the present invention the advantage is arrived at that by means ofone antenna, employed alternately for transmitting and receiving, areceiving operator may cut in upon a message wh1ch 1s belng sent from adistant transmlttlng-station.

The system which I shall describe in this a plication for the purpose ofmore fully dis 0 osing my invention embodies in general the principlesset forth in my Iprior patents, although it will be obvious t at minvention may be employed with any ot er suitable system and that it isnot limited to the system shown herein.

The conductors A, A, which are uninsulated at the top, beingconductively connected by the wire N, constitute the two sides of areceiving-loop antenna, the loop bein closed by the conductors a c L gand --g, respectively. Instead of oundin'g the -receiving system byconnectlng the pomt directly to earth as heretofore has een t e practlcein systems of this general Application and January 2.190s. Serial no.294,098.

'the si es of said loop-antenna.

type, in which one antenna is employed a]- ternately for transmittingand receiving, I find it desirable, and practically necessary, toconnect the receiving-ground lead to the antenna directly below theanchor sparkap and above thetransmitting-helix L, so t at said helixlies between the receiver and the earth. I find that the presence'of thehelix L in the earth connection 9 b e. LE of the receiving system haspractically no effect upon the operation of the receiving system. If,

instead of grounding the receiving system as above set forth, it weregrounded directly, as by connecting the point 9 directly to earth, alarge difference of potential would exist across the responder when thesending system was'in operation and switches of large separation wouldbe required in the conductors a c and a. c in order to protect the resonder.

he receiving-circuit d C R (Z L, including the condenser O, responder Rand any desired portion of the inductance L','is attuned to the periodof the aforesaid receivingloop antenna by the adjustable inductance L orby the adjustable condenser C, or by both; and the adjustable contacts0, 0, de termine the amounts of the inductances L",

L, res ectively, which are to be included in The responder R maycomprise a vessel containing an electrolyte and a glass-inclosed anodeH, which is carried by an iron lunger F sur rounded by the solenoid D.'1 B is a battery and P is a potentiometer. When the key K is depressed,and before it closes the circuit of the generator G at the contact J,the sprin I, carried by and insulated from the kc solenoid D and atteryB at the point h, thereby ener izin said solenoid and causing theplunger to ift the anode H out of the electrolyte. When the key K closesthe circuit of the generator G, the energy of the latter is translated bthe transformer M to the condenser C, whic by dischar ing across the gapS, develops electrical osci lations in the oscillationproducing circuitC S L. The energy of said oscillations is translted is atelephone, v

, closes the circuit of the the anchor spark-gap s, s' is large enoughto maintain the antenna can loop while receiving; but the high tensionat which the oscillations are delivered to the antenna by theablyoftwoplates m, m having a large number of fine teeth, adjacent to a centerplate 11,

to which the antenna lead to the inductance L is connected, 7

Fig, 2, I have shown a form ofadjustable anchor spark-gap which inpractice I have found t be convenient and efficient.

In Fig. 2,.the members 1a,, and m, consist of two saw-hlades set at anangle and adjacent toa center plate n,rthe sides of which preferably arearallel to the saw-blades. By means ofthe screws 2, 2, and the slots 1,1,

the position of the plate a, may be adjusted so as'to vary the length ofthe gap 8, s. It is obvious, however, that the center plate might bemade stationary and! the members m, m, made movable with respectthereto.

It will be obvious that when t e gap s, s'is bridged by theconducting-arc created by the oscillations, there is but negligiblepoten-v tial difference between the points b ands, and betweenthe pointsI) and a, so that the oscillations practically short-circuit thereceivingcircuit and consequently a very small difierence of ot'entialcan exist between the oints d and when the key K is closed. 1; follows,therefore, that a very slight lifting of the glass-covered anodefrom theelectrolyte will sufiice to protect the responder during transmission.When the transmitting-key is in normal position and the solenoid D isnot energized, any signals which may be sent out home distant stationmay be read by the operator at the-station under discussion, who heepsthe telephone T in position while sendt will be obvious that manydifferent types of receiver may be employed; in lieu of the particulartype shown in the drawings and} that many modifications may be made aboth in the transmitting and. receiving systems, as well as in-theantenna and other apgaratus herein described, without departing cm theofmy invention.

I clhim- 1:, In a wireless-telegraph system, a transmitting system, akey or energizing the same, a receiving system, a responder associatedtherewith, and magnetic means, enerciatcd therewith, a plunger carryingone element of said responder, a solenoid coiiperat- I ing with saidHunger and means associated with said key or-energizing said solenoid.

3. In a wireless-telegraph system, a receiving-loop antenna, a closedreceiving-circuit associated therewith, and an oscillation-producingcircuit so associated with said antenna that the oscillations createdthereby in said antenna practically short-circuit the saidroceiving-clrcnit and cause the two sides of the loop-antenna to operatein parallel.

4. In a wireless-telegraph systcnna receivassoci'atcd therewith, anoscillation-producing circuit and means so connecting the latter withthe antenna that the oscillations created thereby in said antennaproduce a practically vneg ible diil'erence of potential between thelation-producingcircuit including a helix, an.

antenna, means connecting said antenna to ground through said helix, areceiving-cm cuit, and means connecting said receivin circuit to groundthrough said helix.

. 8. In a wireless-telegraph system, ananchor spark-gap, an antennaconnectedto one member of saidspark-gap, an oscillation-producingcircuit connects to the othermember of said spark-gap and a receivingcircuit connected to both members thereof.

9. In a wireless-telegraph system, an anchor sparkgap, an antennaconnected-to one member of said spark-gap, anoscillationproducingcircuit, including a helix, connected to the other member of saidspark-gap, a receiving-circuit connected to both members thereof, and aground connection through said helix forsaid receiving-circuit.

10. In a wireless-telegraph system, an. anchor spark-ga comprising amember provided with a p urality of teeth, acooperating lug-loopantenna, a closed receiving-circuit 6o gized by said'key, for moving oneelement of said responder away from the other element thereof;

'2. In a wireless-telegraph system, a transmitting system, a key orenergizing the 65 same, --a; receiving system, a responder assomemberadjacent thereto,'. means wherebw the length of the. spark-gap may bevaried; an antenna connected to one member-ofr'said spark-ga anoscillation-producing circuit connecte to the other memberofsaldsparltgap, and a receiving-circuit connected toboth membersthereof.

' 11. In a Wireless-telegraph system, an anchor spark-gap consisting oftwo members, one member consisting of a plurality of parts each providedwith a lurality of teeth, a cooperating member a jacent to said arts,means'whereby the length of the spar -gap may be varied, an antennaconnected to one member of said spark-gap, an oscillationproducingcircuit connected. to the other member of said sparkap, and areceivingcircuit connected to bot members thereof.

12. In a wireless-telegraph system, an anchor spark-ga comprising amember provided with a p urality of teeth and a cooperating memberadjacent thereto, an antenna connected to one member of said spark-gap,an oscillation-producing circuit connected to the other member of saidspark-gap, and a receiving-circuit connected to both members thereof.

13. Inawireless-telegraph system,atransmitting system, a key forenergizing the same, a receiving system, a responder associatedtherewith, and electrically-operated means controlled by said key formoving one element of said res onder away from the other element thereoi14. In a wireless-telegra h system, a responder comprising two reatively movable elements, a transmitting-key, and elect ricallyoperatedmeans controlled by said key for producing relative movement between theelements of said responder.

In testimony whereof I have hereunto subscribed my name this 29th day ofDecember, 1905.

LEE DE FOREST.

Witnesses:

GBEENLEAF WHITTIER PICKARD, Gno. E. TURNER.

